Building Definition Language

Parameters allow reusable and configurable BDL definitions.

Example:

parameter clear_height: Quantity<Length> = 2400 mm;

parameter stud_spacing: Quantity<Length> = 400 mm;

A parameter shall define:

name;

Type;

permitted range;

default value where allowed;

source;

whether it is overridable;

Examples:

wall_height: @clear_height + 300 mm;

required_area: @Room_101.length * @Room_101.width;

total_load: sum(@Floor_01.members.dead_load);

Expressions may use approved functions such as:

arithmetic;

comparison;

minimum and maximum;

aggregation;

conditional selection;

unit conversion;

geometric transformation;

collection filtering.

An expression shall not:

issue physical commands;

access uncontrolled external data;

modify another Entity;

depend upon nondeterministic execution without declaring it;

conceal an engineering method requiring separate validation.

External analysis results shall be imported as evidence-backed values:

demand.axial:

analysis_result(@StructuralAnalysis_Rev03, "Node_N01", "axial");

Circular parameter dependencies shall be rejected.